1. Field of the Invention
The present disclosure relates to a manufacturing method of a trench power semiconductor device; more particularly, to a manufacturing method of a trench power semiconductor device with shielding electrodes.
2. Description of Related Art
The work losses of current power metal oxide semiconductor field transistors (power MOSFETs) can be classified into two main categories: switching loss and conducting loss. The gate/drain capacitance (Cgd) is an important parameter that can severely affect the switching loss. If the Cgd is too high, it will result in an increase in the switching loss, which in turn limits the switching speed of the power MOSFETs so that it may be harmful for the power MOSFETs to be used in high frequency circuits.
Current power MOSFETs have a shielding electrode located at the lower portion of the gate trench for reducing the Cgd and increasing the avalanche voltage (without sacrificing the on-resistance).